Manufacture of artificial threads or filaments



y 1934- R. w. PAYNE El AL 1,959,443

MANUFACTURE OF ARTIFICIAL THREADS OR FILAMENTS Filed DEC. 12, 1928 2 Sheets-Sheet l FIG l F|G 3 O 5) o\o o o o o o o b h o o o REGINALD W. PAYNE ROB ERT P. ROBERTS Inventors j {KWAM Attorneys May 22, 1934. R. w. PAYNE ET AL 1,959,443

Filed Dec. 12. 1928 2 Sheets-Sheet 2 FIGS- REGINALD W. PAYNE ROBERT P. BER'IS en tOlS y UMJLM Attorneys Patented May 22, 1934 UNITED STATES PAENT MANUFACTURE OF ARTIFICIAL THREADS R FILAMENTS tion of Delaware Application December 12, 1928, Serial No. 325,480 In Great Britain December 23, 1927 12 Claims.

.This invention relates to the manufacture of artificial filaments or threads from solutions of cellulose acetate or other esters or ethers of cellulose by the dry spinning or evaporative method of formation.

In the spinning of such artificial threads or filaments by the dry spinning or evaporative method of formation, solutions of cellulose acetate or other esters or ethers of cellulose in vola- 0 tile solvents are spun into an evaporative atmosphere (usually into a current of heated air) the threads or filaments so formed being continuously Wound up, with or without twisting, on apparatus situated within or outside the evaporative atmosphere. The threads or filaments heretofore produced by such method of spinning have been lustrous in character and have found successful application as artificial silk, artificial horse hair and the like.

The object of the present invention is to produce threads or filaments presenting reduced lustre and more particularly threads or filaments presenting a dull, matt or lustreless appearance, or of considerably reduced lustre.

For this purpose, according to the invention, we perform the spinning by the dry or evaporative method of formation in presence of organic precipitants for the cellulose acetate or other cellulose ester or ether, so that these exert a 30 precipitating action on or in the filaments in the natal state of the filaments.

In performing the invention we may, for instance, add the vapour of the precipitant or precipitants to the evaporative atmosphere.

Or we may, instead of adding precipitants to the evaporative atmosphere, add a precipitant or precipitants to the solution of the cellulose acetate or other ester or ether of cellulose prior to extruding the same into the evaporative atmosphere.

Or again, we may employ the precipitants both in the spinning solutions and in the evaporative atmosphere.

In performing the invention we may employ as the precipitant any organic substance or substances capable of precipitating the cellulose ester or ether from its solution in the volatile solvent employed. Thus, for instance, we may employ alcohols (for instance, ethyl alcohol, cyclohexanol), hydrocarbons (e. g. benzene, xylene, gasoline, petroleum ether), or esters (e. g. butyl propionate), or ethers (e. g. propyl ether), but it will of course be understood that the choice of precipitant will depend upon the solubility characteristics of the cellulose ester or ether thereof and with means for causing a controlled employed and on the relative boiling points of the volatile solvents and precipitants.

According to one form of execution of the invention we spin a solution of a cellulose ester (and. especially cellulose acetate) in acetone or m other volatile solvent or solvents, into an evaporative atmosphere of benzene, petrol or other hydrocarbon vapour and air. In such form of execution we may conveniently extrude the spinning solution in the known manner from fine orificed spinnerets downwards into a heated metier casing or spinning cell through which a current of air is caused to pass, and inject or introduce benzene, petrol or other hydrocarbon vapour into said cabinet or cell, at a point at which the filaments are still substantially wet (i. e. contain a substantial proportion of solvent), in a current regulated to the desired quantity. Instead of or in addition to benzene, petrol or other hydrocarbon vapour we may inject or introduce vapours of alcohol or other organic precipitants into the cell or metier casing or produce the vapours of any such precipitants therein.

In cases where the vapours of the precipitant are produced in the spinning cell by injecting a liquid precipitant, care should be taken to avoid any precipitant from coming into contact with the filaments until it has become vapourized, as otherwise undesirable irregularities are liable to occur in the filaments.

The accompanying drawings serve to illustrate a convenient way of producing delustred artificial silk threads by such a form of execution, i. e. in which the filaments are spun into an evaporative atmosphere of vapour of the precipitant and air. These drawings show diagrammatically a metier of the type composed of a large number of individual spinning cells each provided with spinning jets in the upper part current of heated air to pass in an upward direction counter-current to the filaments; for convenience, two only of such spinning cells are shown in the drawings. 7

Figure 1 is a side view of the metier showing one of the spinning cells in section.

Figure 2 is a rear view of the metier, the back of the metier being shown partly broken away.

Figure 3 is a front view of the metier.

Figure 4 is a diagrammatic plan view of Figme 2 on the line AB Figure 2.

Referring to the drawings 1 is the metier casing which is divided by partitions 2 into a number of spinning cells such as 3 and 3a. Spinning jets 4, 4a etc. are located in the upper part of 11 each cell, two nozzles being shown in each cell, and these spinning nozzles 4, 4a etc. receive the spinning solution via the respective pumps 5, 5a etc. from the supply pipe 6. Each nozzle is con structed with a number of very fine spinning orifices in the usual manner.

Each spinning cell is provided with means for causing a controlled current of air to pass upf ward through the same, these means comprising an inlet such as 7 and 7min the bottom of each of the respective spinning cells, an outlet pipe such as 8 and 8a in the upper part of each of the respective cells, the'outlet pipes communicating with the main draw off or suction trunk 9 and being each provided with a fiow meter, such as 10 and 10a, and a control valve, such as 11 and 11a. The current of "air is heated by means of two steam coils, 12 and 13, which are fitted in the metier respectively near the back and near the front of the spinning cells, each coil extending the complete width of the metier. The sets of filaments 14,14a etc. issuing from the respective spinning jets are led out of the spinning cells through guide eyes or the like such as 15 and pass thence over drawing rollers 16, 16a to their respective cap twisting and winding devices 17, 17a etc. 7 7

Each spinning cell is provided with a number of nozzles 18, 18a etc. serving to introduce vapour of the precipitant from the header 19 into the spinning cells, one nozzle being provided for each of the respective spinning jets. The nozzles 18, 1800 etc. arearranged to inject the vapour of the precipitant into the paths of the sets of filaments issuing from the respective spinningjets, and are fitted at a level at which the filaments are still substantially wet, e. g. 3 inches below the level of the spinning jets. The flow of the vapour of theprecipitant from the nozzles 18, 18a, etc.

is controlled by means of their respective cocks 20, 20a etc.

When producing delustred artificial filaments in such a manner varying degrees of delustration may be obtained according to the amount of precipitant. introduced through the nozzles 18, 18c etc., the temperature of the current of air and other spinning conditions employed. 'Especially useful delustred artificial filaments are produced when 'a 25% (by weight) solution of cellulose acetate in acetone is spun as above described and under the following conditions:- The said solution is extruded through the spinning jets 4, 4a etc. at a rate to yield 50 metres (per filament) per minute of artificial silk. The control valves 11, 110/. are set to cause air to be drawn through the spinning cells 3, 3d at the rate of 22 cubic feet per minute, and the steam coils l2 and 13 regulated to yield a temperature 'between 40 and C. in the neighbourhood of the spinningjets 4, 4a etc. Petrol vapour is in. 'troduced through the nozzles 18, 18a at the rate 'of 101 grams per minute for each nozzle. fil'aments obtained in this manner present 'de- The grees of delustration varying with the temperature employed in the neighbourhood of the spining jets 4, 4a etc. -40' C. the filaments produced are very dull and Thus with a temperature of highly delustred, and the degree of delustration obtained gradually decreases as, the temperature 'in'the neighbourhood of the spinning jets is raised, filaments produced when employing a temperature of 80 C. being slightly delustred.

. According to'another form of execution of the ,invention we may extrudeinto a heated metier casing or spinning cell, through which a current of air is caused to pass, a solution of cellu lose acetate or other ester or ether of cellulosecontaining one or more of the precipitants. In such form of execution the quantity of precipitant will vary according to its'boiling point and its precipitating power on the solution of the cellulose ester or ether employed and with the spinning conditions and the result it is desired to achieve. In general, quantities of precipitant of from about 1% or less-to 40% or more, and preferably from about 5% to 30%, relatively to the volatile solventshould be employed in this form of execution, but itwill be understood that these quantities are only given by way of illustration. The quantities of precipitant employed should of course be sufficient to cause a precipitation of the cellulose derivatives from solution under the conditions of spinning.

The following example illustrates a form of execution of the invention in which precipitants are added to the spinning solution.

EXAMPLE Highly satisfactory threads or yarns presenting reduced lustre may be produced by extruding any of the following solutions into an evaporative at- Solution A r 7 Parts Acetone (99-100% pure) 100 Xylene 20 Cellulose acetate 40 Solution B 1 J Parts Acetone (99-100% pure) 100 Butyl propionate 20 Cellulose acetate 40 Solution C Parts Acetone (99100% pure) 97 Xylene; 23 Cellulose acetate 40 Solution D V 7 Parts Acetone (99-100% pure) s 103 Xylene 17 Cellulose acetate 40 By varying the temperature of the heated air the above solutions will yield filaments showing varying degrees of delustrations. Thus with air at a temperature of 40 .C. the filaments are substantially completely delustred and are of dull or matt appearance, and the degreeor" delustration decreases as the temperature of the air is raised. With air at a temperature of 80 C. the filaments are slightly delustred, and have a highly satisfactory medium low lustre. V

It is to be understood that these solutions are given only by way of example and are in no way limitative.

In performing the invention we preferably Wind the filaments or threads up. (continuously with their formation) with or without twisting, on ap- 'paratus located outside the evaporative atmosphere, thoughsuch winding may be performed *within said atmosphere so desired;

5.. 7 It is to be understood that the inventionis in' no way limited to the particular examples of execution described, which may be varied widely.

The filaments may be extruded either downwards or upwards into the spinning cell or metier casing, and the air current (which may be caused to pass either downwards or upwards through the metier casing or cell) may be heated or warmed therein or prior to admission thereto or both before and during passage through the cell or metier casing. Further, the filaments may be extruded in the same direction as or countercurrent to the air current.

The temperatures to be employed in the spinning cells or metier casings may vary with the boiling point of the solvents and precipitants used, the composition of the spinning solutions and the degree of delustration it is desired to produce in the filaments or threads. Such temperatures may be higher or lower than the boiling point or points of the solvent or solvents employed.

We have found that with spinning solutions containing the more usual solvents such as acetone, methyl acetate or the like, temperatures of about 40 to C. may usefully be employed in the spinning cells or metier casings but we in no way limit ourselves to such temperatures.

By means of the present invention it is possible to obtain threads or filaments showing any desired degree of reduced lustre, from a completely delustred or matt appearance to a relatively high lustre, according to the proportion of precipitant present and the spinning conditions employed.

What we claim and desire to secure by Letters Patent is:

1. Process for the production of artificial filaments presenting reduced lustre characterized in that solutions of cellulose derivatives in volatile solvents are spun by the dry or evaporative method of formation and that at least one organic precipitant for the cellulose derivative is caused to exert a precipitating action upon the filaments in the natal state of the filaments.

2. Process for the production of artificial filaments presenting reduced lustre comprising forming said filaments from a solution of a cellulose ester in a volatile solvent by the dry or evaporative method, said filament formation being effected in the presence of at least one organic precipitant for the cellulose ester which exerts a precipitating action upon the filaments in the natal state of said filaments.

3. Process for the production of artificial filaments presenting reduced lustre comprising forming said filaments from a solution of cellulose acetate in a volatile solvent by the dry or evaporative method, said filament formation being effected in the presence of at least one organic precipitant for the cellulose acetate which exerts a precipitating action upon the filaments in the natal state of said filaments.

4. Process for the production of artificial filaments presenting reduced lustre comprising forming said filaments from a solution of cellulose acetate in acetone by the dry or evaporative method, said filament formation being e1- fected in the presence of at least one organic precipitant for the cellulose acetate which exerts a precipitating action upon the filaments in the natal state of said filaments.

5. Process according to claim 1 and comprising extruding a solution of a cellulose derivative in a volatile solvent into an evaporative atmosphere containing the vapors of at least one organic precipitant.

6. Process according to claim 1 and comprising extruding a solution of a cellulose derivative in a volatile solvent into an evaporative atmosphere heated to a temperature between 40 and 80 C. and containing the vapors of at least one organic precipitant. r

'7. Process according to claim 1 and comprising extruding a solution of a cellulose ester in a volatile solvent into an evaporative atmosphere containing the vapor of a hydrocarbon.

8. Process according to claim 1 and comprising extruding a solution of cellulose acetate in acetone into an evaporative atmosphere heated to a temperature between 40 and 80 C. containing the vapor of a hydrocarbon.

9. Process according to claim 1 and comprising extruding a solution of a cellulose ester in a volatile solvent downwards through orifices into a spinning cell, causing a current of heated air to pass upwards through said cell, and injecting the vapor of a hydrocarbon into said cell at a point at which the filaments are still substantially wet.

10. Process according to claim 1 and comprising extruding a solution of cellulose acetate in acetone downwards through orifices into a spinning cell, causing a current of air heated to a temperature between 40 and 80 C. to pass upwards through said cell, and injecting gasoline vapor into said cell at a point at which the filaments are still substantially wet.

11. Apparatus for the production of filaments presenting reduced lustre, said apparatus comprising a spinning cell, spinning orifices arranged at one end of said cell, means for causing an evaporative atmosphere to pass through said cell, means for heating said atmosphere in its passage through said cell, and means for injecting vapors of an organic precipitant into said travelling atmosphere at a point near said spinning orifices.

12. Apparatus for the production of filaments presenting reduced lustre, said apparatus comprising a spinning cell, spinning orifices arranged at the top of said cell, means for causing an evaporative atmosphere to pass upwards through said cell, means for heating said atmosphere in its passage through said cell, and means for injecting vapors of an organic precipitant into said travelling atmosphere at a point near to said spinning orifices.

REGINALD WILLIAM PAYNE. ROBERT PIERCE ROBERTS. 

